Japanese Laid-Open Patent Application No. 2011-216304 discloses an electronic power supply device configured to supply electric power stored in battery cells to an electronic power equipment, such as electric pruning clippers and electric hedge clippers. As shown in FIG. 31, this known electronic power supply device includes an electronic power supply pack 100 made of cloth which can be carried on the operator's back. Furthermore, a battery pack 102 having a plurality of battery cells, a mounting unit 104 configured to be slidably mounted onto the battery pack 102, and a controller 105 are housed in the electronic power supply pack 100. An output connector 106, to which a power cord (not shown) of the electric pruning clippers etc. is connected, may be located in the controller 105. According to this configuration, electric power stored in the battery pack 102 can be supplied to the electric pruning clippers, etc. while the power cord of the electric pruning clippers, etc. is connected to the output connector 106 of the controller 105.
The above-described electronic power supply device is configured to house the battery pack 102 in the electronic power supply pack 100 that is made of cloth. As described above, the battery pack 102 may be configured to be slidably mounted onto the mounting unit 104. Accordingly, the battery pack 102 may include a slit-shaped opening, into which an electric power supply terminal such as the mounting unit 104 is insertable. The battery pack 102 may also include ventilation openings, through which air supplied by a charger (not shown) can pass to cool the battery pack 102, for example, while it is being charged by the charger. However, such ventilation openings may adversely affect the water tightness of the battery pack 102 that houses the battery cells. In addition, the electronic power supply pack 100 in which the battery pack 102 is housed may be formed of cloth that is water resistant but is not entirely waterproof, and thus it may be difficult to adequately protect the cells in the electronic power supply device from damage caused by the ingress of water/moisture. As a result, the battery cells in the battery pack 102 may become wet, and the reliability or durability of the cells may be reduced, e.g., due to electrolytic corrosion.
Furthermore, because the electronic power supply pack 100 is made of cloth, the cloth may not sufficiently absorb a shock or impact if the electronic power supply device is, for example, accidentally dropped, such that the battery pack 102 and the battery cells could be subjected to a significant impact in this event. In case the battery pack 102 houses multiple battery cells, the battery pack will be quite heavy and thus will potentially suffer from a substantial shock if dropped. The resulting damage may cause a malfunction.
In view of the above, there is a need to provide improved water protection for the battery cells of an electronic power supply device and also to protect the cells from impact damage by more effectively absorbing, dissipating and/or deflecting the impact energy if the electronic power supply device is dropped.